Spitballing from a comment I made.
What if Vanguards got a temporary HP pool very similar to an energy shield and their abilities keyed off of the status of that shield.
Concept:
Entropic Bubble: You attract a field of entropy around yourself that protects you from harm. Depleting the field allows you to more easily manipulate the entropy of the battlefield.
You gain a pool of temporary HP equal to your Vanguard level, which replenishes at a rate of 1/round, increasing as you level.
Certain vanguard disciplines can only be used when the shield is depleted. (Previously ones with an EP cost)
As a move action, you can absorb the field and gain access to certain vanguard disciplines.(Previously ones with an EP cost)
Benefits:
1. You don't have to track a new resource pool, it's the same rules as energy shields.
2. You have something making you "tanky" even before you start taking hits.
3. You can drop your shield each round with a move action to open up your cool abilities.
4. When you take damage your shield is dropped for you and you can move and act, or do two actions, making being in the thick of things still feel good.
5. Desiring temporary HP loss doesn't equate to you being a masochist.
6. You could have some abilities usable while the shield is partially damaged, versus fully depleted.
7. You could make builds and abilities that keep the shield up for more "tankiness" and others that deplete it faster for more bang.
Drawbacks:
1. It's not as unique
2. It might be hard to tune how many HP should be in the shield.
3. They might need to reduce the class's innate stamina and HP.
4. Might not interact well with the addition of regular energy shields.
What do you guys think?